The knee osteoarthritis has high prevalence, which tends to increase with the aging population. The limited efficacy of pharmacological interventions stimulates the search for other options, in order to increase the therapeutic success. Acupuncture is widely used for pain control in several pathologies. A modality of intramuscular stimulation to quantify the intensity of the stimulus is electro acupuncture (EAC) that the intensity of 2 Hz accelerates the release of enkephalins, endorphins and beta-endorphins. The application of electric currents to modify brain function is a very old technique. The transcranial direct current stimulation (tDCS) is based on applying transcranial direct weak current (usually above 2mA) through electrodes in a non-invasive, simple and painless. Other advantages include low cost and the possibility of a placebo reliable. The purpose of this study is to evaluate the ability to reduce pain and improve functionality in chronic pain for knee osteoarthritis with two techniques, one that promotes a bottom-up approach (EAC) and other top-down (tDCS). We will seek to analyze the efficacy of them separately and together, seeking summation of results.